Bond for concrete-construction forms.



0c M. MARKHAM. BOND FOR CONCRETE GONSTRUOTION FORMS.

APPLICATION FILED NOV. 25, 1908.

@fififiQQ. Patented July 20,1909.

CHARLES M. MA-RKHAM, OF cHioAeo, ILLINOIS;

BOND FOR CONCRETE-CONSTRUCTION FbRMS.

Specification of Letters Patent.

Patented July 20, 1909.

Application filed November 25,1908. SerialNo. 464,438.

To all whom it may. concern:

Be it known that I, CHARLES M. MARK- HAM, a citizen of the United States, residing at Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Bonds for Concrete-Construction Forms, of which the following is a specification.

My invention relates to forms for concrete construction and more particularly to improvements in devices commonly known as bonds employed in the process of such tion of columns.

construction for clamping or holding segments of a form together.

- The ob'ectof my invention is to provide-a device 0 the-character mentionedso con-- structed as to be es ecially applicable to forms employed in t e concrete construc- A further object of invention is to provlde a device of the character mentioned adjustably constructed, the same being so de- 4 signed as to adapt the same to be applicable to a column form of any diameter.

A still further object of my invention is to provide a bond which may be readily and uickly a plied to or moved" from aform, t 0 same 'eing adapted when in use to rigidly and securely hold in. position the seg ments of the form, In objectbein to provide a bond which wil be'of the hig est possible efliciency and one which will be simple of construction, hence of low cost to manufacture.

Other objects will appear hereinafter.

With these objects in view my invention consists generally in a flexible metallic band or strap of such a length as to be adapted to encircle an ordinary column of the maximum diameter. I

My invention further consists in a clamp or look rovided at one end portion of said band, t e same being adapted to securely grip or hold the opposite end portion of said band in such amanner as to revent the enlargement of the loo former thereby.

My invention furt er conslsts in certain details of construction and arrangement of form to which is applied the preferable form of my device: F g. 2 is a top lan view of the bond detached, portions of t ie same being broken away so as to better illustrate its construction. Fig. 3 is a detail cross sectional view of the cam lever thereof, and i Fig. 4. is a. detail of an end portion of the clamp base.

Referring now t6 the drawings, myinvention consists in a flexible metallic band or strap 1 to one end 2 of which is securely fixed, preferably by means of rivets 3, the base portion 4 of a clam or lock 5. Said band maybe of any suitable length but is preferably of such length as toadapt the same to encircle a column form of the largest diameter ordinarily constructed, and though flexible,,should be of great tensile strength. In order to receive said end portion 2 of the band and permit the device ,to lie close against the form, the inner surface of said base. portion 4 is preferably channeled as at 6, as clearly shown in Fig. 20f tl1e accompanying drawings, thereby bringing the inner surface ofsaid band flush with that of said clamp ortion 4 The outer end of the member or ass 4 is provided with parallel ears 7 which extend outwardly therefrom.

Pivotally secured between said cars is a cam lever 8. Said lever is -so constructed that by forcing the shank thereof inwardly causes the cam face 10 of the end portion 11 thereof to clamp the free end 13 of the band firmly against the inner surface of the wall 12 of the clam base 4 as clearly shown in Fig.2. It shou d be noted that the wall 12 between the cars is outwardly tapered so that the strap 1 shall lie close against the form until it is practically within the clamp. I

In order to guard against accidental re leasemcnt of said cam lever I provide an eyebolt 14, the eye 15 thereof being pivotally secured to the clam with a lug 16 preferably formed integrally with said base at the upper edge portion thereof, and by cutting away or recessing the base each side of the lug as shown in Figs. 2 and 4. Slidably mounted upon. the outer end portion of the bolt 14 is a dog 17 having a recess or groove 18 formed in the'inner surface thereof to engage a projecting flang 19 formed upon the upper outer edge of saidbase 4 by engagement lever shank Q-and extending longitudinally thereof. A thumb nut 20 is threaded upon the outer end portion of the member 14 and engages with said dog to hold the latter in engagement with said flange end to hold the lever in position. Y

'By the provision of a bond of a construction as described it is evident that after once applying the same to e mold (any suitable means being employed to tighten the loop thereof around the form) any outward pressure upon the form segments, as is ordinarily the case upon filling the form With concrete, tends only to more securely lock. the end por tion 13 of the band 1 in the clamp 5 of the bond, resulting in obvious advantages. By the provision of a bond of such construction the size of the form upon which it is used is immaterial it being adapted to serve just e'fliciently in conjunction with a form of small. diameter as upon one of greet diameter,-this I being of great financial as well as practical advantage when it is taken into consideration that at the present time in the concrete construction of columns it is necessary to employ separate bonds for eeeh'of the forms of different diameters.

While I have shown What ldeein to be the )reiereblc form of my device I do not wish to e limited thereto there might be many changes made in the details of construction Without departing from the spirit of my in vcntion. 1 also Wish it understood though I have designed my device with special reforenee to forms for concrete construction I may use it for any other purpose to which it is applicable.

supoort, a dog and thumb nut carried by said bolt, said dog, being adapted to engage the shank of said lever, substantially-wand for the purpose specified.

2. In a device of the class described, a flexible strep, e member secured to one end thereof, a pair of outwardly-extending ears on said member, a cam lever pivotally mounted between said ears and adapted in one position to clamp the free end of the stra against said member, an eye bolt, pivotal y conneetei'l Lo-said member, a flange on said lever, 'a dog adapted to engage said flange and a thumb nut on said bolt adapted to engage paid dog, said dog being grooved to receive said flange, substantially as (10- 6( scribed.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses;

ClrlAliLllS M. M Al'lKll AM Witnesses:

HELEN F. LrLms, JANET E. HOGAN. 

